1. Field of the Invention
The present invention relates to a high frequency switching circuit and a method of controlling the same.
2. Description of the Related Art
Recently, the reduction of power consumption in miniaturized wireless communication devices such as mobile phones and the like has become important. Since wireless communications devices transmit or receive information by switching switches at a high speed, a considerable amount of power is consumed in the switches and a driving circuit therefor.
Generally, mobile phones include a transmitting mode, a receiving mode, a transmitting and receiving mode as a communication mode, and a field effect transistor as the switches switch a transmitting/receiving circuit connected to an antenna at high speed, every time the communication mode is changed.
In addition, the field effect transistor is connected to a voltage up circuit or a voltage down circuit (negative voltage generation circuit) as the driving circuit. The voltage up circuit mainly improves transmit power supplied to the antenna from a transmit circuit. Meanwhile, the voltage down circuit mainly improves output characteristics in a state in which the field effect transistor is turned-off.
As a technology for reducing power consumption in the voltage up circuit, technology disclosed in Patent Document (Patent Document: Japanese Patent Laid-Open Publication No. 2008-35560) has been applied. In the high frequency switching circuit described in the Patent Document, a voltage up circuit is operated at the time of a transmission requiring a large amount of power but is not operated at the time of signal reception not requiring a large amount of power, thereby reducing power consumption.
However, the high frequency switching circuit of the above-mentioned Patent Document may be applied to reduce power consumption at the time of signal reception but not reduce power consumption at the time of signal transmission. Therefore, a communication system such as the Universal Mobile Telecommunications System (UMTS), in which, for example, the voltage up circuit or the voltage down circuit needs to be operated at all times, may not use the high frequency switching circuit described in the above-mentioned Patent Document.